This invention relates to door closure mechanisms and more particularly to a mechanism and construction for a door and frame whereby closure may be effected in a radiation resistant manner.
RF shield mechanisms utilized in enclosures in conventional use today experience unreliable performance due to improper use of materials, marginal design and inability of closures to withstand constant usage. The present construction techniques result in a high incidence of mechanical failure whereas the use of improper materials result in marginal electrical performance and are subjected to continuous degradation. Typical configurations have employed step joint constructions having pluralities of metal strips along the step contacts between door and frame, and sliding arrangements where each of the abutting sliding contacts include strip-like metal portions forming a closure seal between the door and frame. In the U.S. Pat. No. to C. A. Hansen, 3,589,070, issued June 29, 1971, a radiation resistant enclosure is constructed of two strips of oppositely offset resilient friction engaging elements which must be fitted into specially designed channels formed as elongated grooves along both sides of a holding slot designed to accommodate these members. These construction techniques require extensive soldering, positioning and fabricating techniques and are difficult to align, maintain and repair.
It is accordingly the object of the present invention to provide a novel and unique enclosure design resulting in a rigid lightweight construction.
It is another object of the present invention to provide material selections compatible with magnetic, electric and plane wave performance characteristics.
It is a further object of the present invention to provide a construction of minimal friction, but with maximized electrical continuity between the door and frame assembly.